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Preparation of Janus Particles and Alternating Current Electrokinetic Measurements with a Rapidly Fabricated Indium Tin Oxide Electrode Array
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Shear-Induced Alignment of Janus Particle Lamellar Structures
Ronal A DeLaCruz-Araujo1, Daniel J Beltran-Villegas2, Ronald G Larson2
1Department of Chemical Engineering, University of Puerto Rico-Mayagüez , Mayagüez, Puerto Rico 00681, United States.
Langmuir : the ACS Journal of Surfaces and Colloids
|October 28, 2017
Summary
Shear flow controls Janus particle lamellar structures, shifting from random to parallel and then perpendicular orientations as flow strength increases. This transition, driven by hydrodynamic and Brownian forces, is key for reconfigurable materials.
Area of Science:
- Colloid science
- Materials science
- Soft matter physics
Background:
- Colloidal structures are vital for advanced reconfigurable materials.
- Controlling their alignment is a key challenge.
Purpose of the Study:
- To investigate the shear flow-induced alignment of Janus particle lamellar structures.
- To understand the relationship between flow conditions and lamellar orientation.
Main Methods:
- Brownian dynamics simulations were employed.
- Lamellar alignment was quantified against Péclet number (Pe), particle volume fraction, and interaction potential strength.
Main Results:
- Three orientation regimes were identified: random (low Pe), parallel (intermediate Pe), and perpendicular (high Pe).
- The transition from parallel to perpendicular alignment was found to be independent of particle volume fraction.
- This transition is governed by hydrodynamic and Brownian torques overcoming interparticle interaction torques.
Conclusions:
- Shear flow effectively controls the orientation of Janus particle lamellar structures.
- The findings provide insights into the mechanisms of shear-induced alignment in colloidal systems.
- This work has implications for designing reconfigurable materials with tunable properties.
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